Research

Research progress in the Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology is focused on topics to advance agriculture and public health in Mississippi, the southern region and the nation. The departmental faculty addresses a wide-range of research topics ranging from pest and plant interactions, human diseases and public health, commodity improvement (e.g., rice, cotton, corn, biofules, etc.), taxonomy and systematic biology, environmental toxicology, molecular biology and pharmacology.

Click on the area of research to explore our discoveries.

Biochemistry and Molecular Biology

Advancing Amphibian Populations Through Reproductive Research

Amphibian population declines are being reported across the globe at an alarming rate. Disease, climate change, pollution and habitat destruction all contribute to what is thought as the biggest mass extinction event since the demise of the dinosaurs. Scientists worldwide are stepping in to try and rescue threatened species from the risk of extinction, including a collaborative team from Mississippi State University and the Memphis Zoo.

Scientists with the MSU Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology are attempting to increase populations of a number of vulnerable species held in captive breeding programs, including one of the most critically endangered species in North America—the Mississippi gopher frog (Rana sevosa). Only 125 adults are thought to remain in a single pond in Harrison County, MS. Thus, captive assurance and breeding colonies being established at MSU are necessary for reintroduction and recovery programs. Unfortunately, encouraging frogs to mate naturally in captivity is not always easy as they rely on seasonal cues to stimulate breeding behavior, which can be difficult to replicate in artificial environments. Instead, assisted reproductive technologies, such as exogenous hormone administration, are used to bypass these cues and induce the production and release of sperm and eggs for in vitro fertilization. The ability to collect gametes in this way also allows researchers the opportunity to investigate protocols for the long-term frozen storage of sperm and embryos through cryopreservation. Development of successful gamete freezing techniques would facilitate the genetic management of captive populations and provide a genome resource bank as a security measure against loss, ensuring the long-term conservation of threatened amphibian species.

Developing Reproductive Technologies for Salamanders

Almost 50% of salamanders worldwide are currently threatened with extinction, making them the most threatened order of amphibians. Scientists at MSU, in partnership with the Memphis Zoo, are dedicated to improving Amphibian Reproductive Technologies (ART) in the hopes of increasing the breeding success of endangered salamanders due to poor reproductive success in captive assurance colonies and the growing loss of genetically valuable founders.

Model species like the tiger salamander (which can grow up to a foot long!) are being studied to improve reproduction protocols. These protocols will initially be applied to four targeted endangered salamander species native to the United States. Most ART research to date has been focused on frogs and toads; hence, little is known about the reproduction of salamanders, resulting in a wide open field for learning more about their reproductive ecology.

When successful, this research could lead to the breeding and release of captive born salamanders to the wild in order to bolster threatened populations. This unique partnership between the Memphis Zoo and MSU are creating opportunities for graduate students, undergraduates and post-doctoral fellows to get experience at the cutting edge of basic and applied science with conservation impacts.

Luminating Infections in Pregnant Mares

Infections are the leading cause of abortion, stillbirth and preterm delivery in mares. MAFES scientists have developed a new approach to understanding the infection process in pregnant mares by using biophotonic imaging and modified bacteria with luminescent characteristics. In other words, the technique allows researchers to capture real-time pictures of glowing bacteria as they spread through a mare's body. The method allows scientists to track pathogens in a minimally invasive procedure.

MSU professor finds pandas may aid biofuel production

MAFES scientists are looking to "panda poop," or microbes in panda excrement that breakdown woody materials, as a possible means to biofuel production. Scientists recently discovered that microbes in panda feces are strong enough to break down the toughest plant materials. Panda poop might help overcome one of the major challenges to producing biofuels: breaking down the raw plant materials used to make the fuels.

The findings have garnered national attention as the reproduction of these microbes could contribute to developing alternative fuels that don't interfere with food crops and could also save a great deal of money. One of the most expensive processes in making biofuels is the pretreatment, where sugar polymers are chemically treated so that they can be used to make ethanol or oil. If you can insert a microbe that does that naturally and efficiently, production costs for alternative fuels would be cut tremendously.

MSU researcher's study leads to swamps, 'gators'

A Mississippi State University biologist's fascination with crocodiles has brought together researchers from the United States and Australia to study the genetic building blocks of a reptile order. In the process, they hope to discover ways to conserve endangered animals, harness the antibiotic properties of alligator blood and isolate the genes that determine gender.

Ray recently received funding from the National Science Foundation for a collaborative project with other scientists involved in crocodilian research. Each researcher hopes the genetic information stored in the crocodilian genome will answer different questions. Ray is most interested in the role DNA plays in the body shape of all crocodilians.

Such significant genetic information could have an impact on wildlife conservation, including ways to preserve one of the research subjects, the gharial. This crocodilian is visibly different from its relatives, with completely webbed rear feet and a long, tapered snout that ends in a soft bulbous nose in males of the species.

MSU working to increase endangered toad numbers

Plastic storage crates in a sunny lab at Mississippi State University are the new homes of 52 endangered Boreal toads, native to the Colorado Rockies. Boreal toad numbers have dwindled to dangerous levels in recent years, and MAFES scientists have partnered with the Memphis Zoo to find a way to increase the population.

We're trying to optimize the reproduction protocols for these toads. We want to get the toads to reproduce in captivity so the young can be raised and released to the wild. In Colorado, they usually hibernate naturally from November to summer, and this is believed to be a major trigger of their reproductive cycle.

Scientists are trying to figure out what hormones to use to get the Boreal toads to reproduce in captivity without hibernation.

Muscadine Juice Prevents E. Coli

Finding natural antimicrobial compounds in fruit to enhance the safety of its juice is of great interest to the beverage industry because Escherichia coli, which causes foodborne illness, can survive in acidic environments for long periods. Muscadine grape is indigenous to the Southeast and contains a large variety of antioxidant phytonutrients. MAFES scientists found that red muscadine juice has natural antibacterial substances and suggest that these can be used as active antimicrobial ingredients against E. coli in nonalcoholic beverages.

Safer Horse Transportation

There has been little research to measure the heat conditions in horse trailers during transport. MAFES scientists recently measured several temperature variables in a fully enclosed four-horse, ant-load trailer with and without animals. Scientists found that trailer temperatures during transport exceeded those recommended for animal housing, although the thermal environment was affected by vehicle speed, vent configuration and presence of animals. They found that temperature increased significantly in transport during relatively mild weather, which indicates that horses could suffer from heat stress during warmer weather. These results show the importance of closely monitoring heat conditions in trailers used to transport horses.

Snap, Crackle, Pop! Conversations in a Rice Cell

Do you remember commercials for Rice Krispies cereal? They featured the elf-like characters Snap, Crackle, and Pop who were named after sounds the cereal reportedly makes when milk is added. Dr. Zhaohua Peng does not study Rice Krispies, but his research group is studying the molecular "conversations" that occur between a rice cell wall and its nucleus. The cell wall protects the cell and gives it rigidity. If the cell wall is removed from a rice cell, a new cell wall is synthesized. The rice nucleus contains chromatin, a mixture of proteins and DNA. The genetic information of each rice cell is stored within its genes (coded in its DNA), and which genes within chromatin are active is controlled, in part, by the way that chromatin within the nucleus is packaged. Dr. Peng and his research group have shown that removal of a rice cell wall results in substantial changes in the organization of the chromatin within the nucleus. This suggests that when the nucleus "learns" that the cell wall has been removed, it undergoes major chromatin restructuring, presumably to allow those genes involved in cell wall synthesis to be utilized in the process of cell wall resynthesis. It is unclear how removal of the cell wall is detected by the cell and how the message, "Hey, someone stole our cell wall!" gets from the cell periphery to the centrally-located nucleus. While Snap, Crackle, and Pop may be involved, it is more likely that communication is the result of interactions between various macromolecules. Dr. Peng's team is currently working to identify these macromolecules and describe how they interact with one another.

Toxin-free castor would be major help to industry

Castor oil is the highly desirable, plentiful product of castor beans. The oil is used to produce everything from cosmetics and paints to jet aircraft lubricants and certain plastics. The thick oil makes up 60 percent of the seed's weight. By comparison, high-oil corn or canola only produce about 25 percent oil by weight. Ninety percent of the oil is ricinoleic acid, a fatty acid found in large quantities only in castor oil. This acid has many industrial applications.

MAFES scientist are trying to make it possible to grow the plant safely for commercial oil production in Mississippi. Castor seed meal, not the oil, contains ricin, a toxic protein that can become fatal if untreated in the body.

To make castor a commercially viable U.S. crop, scientists are trying to discover a way to genetically modify the plant so that either the gene that produces the toxin is no longer expressed or the toxin is no longer produced.

One of the challenges is that castor resists being transformed. The genetic modification process involves inserting a fragment of DNA foreign to the plant into the genetic code, where it must be accepted and become active.

Everything from cotton to corn and soybeans has been genetically modified, but castor is much more difficult. The castor cells can be transformed, but you can't get whole plants to grow from the cells.

Entomology

A soldier in the fight

The black soldier fly, which turns agricultural waste into viable protein that can be used in feed for livestock such as chickens, may help fight food insecurity. John Schneider, Mississippi Agricultural and Forestry Experiment Station and professor of entomology in the Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, is evaluating how to integrate the insect into food production systems. According to Schneider, studies indicate that the insect is a high quality food source with no side effects. He hopes the research will help close the ecological loop, providing an efficient way to reduce agricultural waste and produce livestock feed.

Ant study at Noxubee refuge suggests healthy ecosystem

It is no secret that many ants live beneath the leaves, bark and soil of the Noxubee National Wildlife Refuge, but no one knew how diverse the population was until Mississippi State University entomologists dug up the facts.

Their findings show that imported fire ants and other exotics have not displaced the natives. More importantly, the distribution and diversity of ants at the refuge indicate a well managed, healthy ecosystem.

Scientists estimate that ants make up 10 percent of the terrestrial animal biomass on the planet. Ants are important to ecosystems because they decompose waste, aerate soil and bring in needed nutrients, disperse seeds, kill large numbers of other insects and are food for many animal species. Their distribution and diversity often indicate an ecosystem's ability to maintain itself.

Asian Beetle Threatens Coastal Trees

A beetle that made its presence known in Mississippi this summer is threatening the extinction of red bay trees in the state. The beetle is the red bay ambrosia beetle, a dark brown insect about half the size of an uncooked grain of rice. It spreads the pathogen that causes Laurel wilt disease in many tree species, including Mississippi's red bay and sassafras trees. MAFES scientists are trying to determine how the beetle got into Mississippi so it can be stopped.

High-protein insect studied at MSU

Imagine an insect that can eat nearly anything, control microbes, live off of water alone in the adult stage, and be a good source of protein for animal feed. The black soldier fly is real, not science fiction, and it has researchers at Mississippi State University abuzz with excitement. MAFES scientists are studying the black soldier fly as a potential solution to dealing with large amounts of waste while also generating a feed product. Black soldier flies are 40 to 45 percent protein by dry weight. Theoretically, one metric ton can be produced per day in the space of a medium-sized house, and used as a feed product.

Harvested larvae can be dried and milled to create a high-protein meal for livestock, poultry and aquaculture consumption. Due to their high oil content, black soldier fly larvae may even be useful for biofuel production. They're not a known disease carrier, they don't bite or sting, and they're not a nuisance. They're a versatile species with huge potential.

Black soldier fly larvae will eat almost anything—manure, carcasses—without any remaining harmful fungi or microbial residue. These insects require no special diet, so they can be fed nearly any kind of agricultural byproducts or waste.

Identifying Destructive Invaders

Exotic insect species enter the United States through multiple routes, such as on wood shipping pallets, plant materials, and imported fruits and vegetables. The U.S. government sets trade restrictions to help prevent the introduction of nonnative pests, and its inspectors work at all borders to search for and confiscate materials carrying these insects. Some hidden pests do make it past inspection and move into U.S. crops. Once established, these pests can damage crops and native plant species, ultimately causing severe economic damage. Quick identification of invasive species is crucial to stopping their spread. The Mississippi Entomological Museum was recently designated as the Eastern Region Identification Center for the USDA's Animal and Plant Health Inspection Service.

MSU Research Takes the Bite Out of Mosquitoes

Since 1999, the United States has had 30,062 cases of West Nile virus, according to the Centers for Disease Control and Prevention. Of these cases, 1,247 were fatal. Mississippi has had 842 cases, including 48 fatalities.Like malaria, West Nile virus is spread by mosquitoes. West Nile virus and malaria cases together make mosquitoes the world's No. 1 vector for disease transmission. After Hurricane Katrina, coastal states became prime mosquito-breeding grounds, creating the possibility for a spike in West Nile cases and associated deaths.

The Mississippi Department of Health (MDH) held mosquito-education workshops throughout the state. The agency conducted pre- and postgrant surveys designed to gauge practices, knowledge and attitudes of local personnel in mosquito- control programs before and after disbursement of funds. Postdoctoral associate and veterinarian Kristine Edwards and associate Extension professor Jerome Goddard conducted research and workshops based on survey responses.

The study provided guidelines for cities to combat the disease-carrying pest. Steps include first surveying to find which ditches have mosquitoes, and then spraying larvicides to kill larvae in the standing water. The final tactic is spraying adulticides to kill mature mosquitoes.

The guidelines also recommend adult mosquito trapping, which captures seven to 10 mosquitoes on a typical night. When the count swells to 50 to 100 specimens, usually a week after a good rain, it is time to spray. Edwards said simple tactics like surveying and trapping can save local governments time and effort.

MSU researcher finds new grasshopper species

When JoVonn Hill stepped out of his vehicle in a cedar glade near Nashville, the first insect that crossed his path was a grasshopper never before identified. He gave the grasshopper the scientific name Melanoplus ingrami, honoring Wayne "Buddy" Ingram, an interpretive officer and naturalist at the Cedars of Lebanon State Park. Ingram has extensive knowledge of the area and was very helpful to Hill on several trips to the park.

Entomologists at MSU have been finding and naming new species for the last 100 years, and this includes several hundred species of beetles, moths, leafhoppers, wasps and other insects. JoVonn and four others currently on the staff of the Mississippi Entomological Museum have described and named about 20 new species in recent years.

Each species, from the smallest microbe to humans, plays an important role in maintaining biodiversity and keeping the earth healthy.

Plant Pathology

Corn researchers develop in-field aflatoxin approach

MAFES scientists are researching new ways to reduce aflatoxin in infected corn. Corn is one of the state's leading row crops, but it is susceptible to aflatoxin, a fungus that can reduce profits and hurt marketability.

Aflatoxins are naturally occurring chemicals produced by the fungi Aspergillus flavus and A. parasiticus. The fungi appear as yellow-green or gray-green molds on corn in the field or in storage. Scientists are applying granules of Aspergillus flavus that do not produce aflatoxin but do compete with the native Aspergillus flavus. In essence, they are using a good fungus to fight a bad one. Aflatoxin levels are not normally high in corn, but Mississippi's hot, humid climate encourages the growth of the fungus that produces the toxin. Heat, drought, high humidity, insect infestation and anything else that stresses the crop favor fungal growth.

Aflatoxin can build up in crops such as corn, cotton, peanuts and tree nuts. Aspergillus infects corn by invading through corn silks or through insect damage to kernels or ears. Using non-aflatoxin-producing A. flavus strains has the potential to protect much of the state's corn harvest.

Cotton yields increase with new technology

Researchers at Mississippi State University have developed technology that uses reflected light to analyze the presence of certain nematodes in cotton fields so producers can increase profits. Since 2001, MAFES and MSU scientists have been developing a way to use remote sensing technology to battle reniform and root-knot nematodes, which are the No. 1 cotton pest in Mississippi, Alabama and Louisiana. In recent years, Mississippi cotton producers lost more profits from these nematode infestations than any other state, including a loss of 225,000 bales worth $87.8 million in 2006.

Compared to the nematode counts, the data collected through hyperspectral imaging was 75 to 100 percent accurate. The data was used to generate a field map showing areas of low, medium and high nematode populations. From that, a prescription map for applying different amounts of nematicide was created. For the producers, the yields were higher, which increases profits. Plus they saved money by applying only the amount of chemical required rather than blanketing their field with the amount needed to treat the highest population of nematodes found in their soil samples. The third benefit is to the environment, because site-specific applications reduce the amount of chemical used.

This research benefits not only Mississippi, but the entire Southeast, as producers in Alabama and Georgia routinely use the site-specific application method for treating their fields.

MSU research benefits poinsettia producers

Researchers at Mississippi State University have found a cost-effective and environmentally friendly strategy for fighting one of the most serious soil-borne diseases in poinsettia production. Pythium stem and root rot is a common problem in poinsettia production because the fungus thrives in cool, saturated and poorly drained soils. MAFES researchers found a way to use organic methods and fewer fungicides to successfully fight this pathogen.

Pythium is a widespread fungus. Plants are cross-contaminated by splashing water or soil from pot to pot. In nursery management, producers treat the plants when they transplant cuttings to the pot. Once the disease is established, it is too late to treat, so growers have to use a fungicide early in the season to make sure they have a healthy crop. The standard conventional fungicide is effective but expensive, and there is a high risk that the fungus will become resistant to the chemical.

Managing resistance to important fungicides is a key component of a disease management program. One of the strategies MAFES scientists are researching is integrating biofungicides. Biological agents are not conventional fungicides or chemicals, but organic methods of fighting fungi or other harmful microorganisms. The study found that a reduced rate of the conventional fungicide, when used with a biological agent, resulted in plants that didn't rot and had similar growth to the label rate of conventional fungicides. This is beneficial to growers because it reduces their impact on the environment. It also reduces the risk of the pathogens adapting to the fungicides and becoming resistant and may save producers money by reducing the amount of fungicide they use.

New research to aid state's soybean growers

Tiny soybean cyst nematodes cause big problems for soybean growers, but a Mississippi State University researcher is helping cut them down to size. The soybean cyst nematode, or SCN, is a small, plant-parasitic roundworm that attacks the roots of soybeans. Affected plants have stunted growth, wilt and often die. SCN has been a problem for Mississippi growers since the 1950s, and there is no known method of eliminating nematodes from the soil. Growers rely heavily on crop rotation and other farm management techniques to minimize damage. The dilemma has researchers interested in developing new soybean varieties.

It could be a few years before the new varieties developed will be fully tested and commercially available, but scientists are also working on other research that can assist farmers with current crop rotation techniques.

There are 16 types of SCN, commonly called "races." These races differ in their ability to reproduce on certain soybean varieties. Many fields have more than one SCN race in them. One race may be dominant with other minor races present. SCN can change races, depending on the available food sources. Therefore, growers must test their soil before planting in order to choose varieties that are not susceptible to the particular nematodes in their fields. Scientists have developed a new test that uses a gene marker technique that can identify nematode races in a molecular laboratory in a matter of hours.